The axis of bubble tube must be perpendicular to the vertical axis.

Related MCQs

• If altitude bubble is provided both on index frame as well as on telescope of a theodolite, then the instrument is levelled with reference to i) altitude bubble on index frame ii) altitude bubble on index frame if it is to be used as a level iii) altitude bubble on telescope iv) altitude bubble on telescope if it is to be used as a level The correct answer is
• The sensitivity of a bubble tube can be increased by
• With the rise of temperature, the sensitivity of a bubble tube
• An imaginary line tangential to the longitudinal curve of the bubble tube at its middle point is called
• When the position of a point is to be located accurately by a perpendicular offset, the direction of perpendicular is set out by means of
• The process of turning the telescope about the vertical axis in horizontal plane is known as
• The operation of revolving a plane table about its vertical axis so that all lines on the sheet become parallel to corresponding lines on the ground, is known
• The process of turning the telescope of a theodolite over its supporting axis through 180? in a vertical plane, is called
• The axis of telescope level must be
• The line of collimation must be parallel to the horizontal axis.